THE NATION

Agency Sees Transit, Rail System Threat

Terror: Transportation Department says its warning is based on unconfirmed data.

WASHINGTON — The Department of Transportation has issued a warning about possible attacks on rail and transit systems across the country, law enforcement officials said Thursday.

The department's warning was based on unconfirmed and uncorroborated information, one law enforcement official said.

"It involves rail and transit systems ... and is about possible attacks," he said.

The Department of Transportation consulted the FBI before issuing the warning, but the FBI did not put out a matching alert or advisory to law enforcement officials across the country, the official said.

He did not have details on how many cities' transit systems were being put on alert.

This is the latest in a series of warnings eight months after hijacked airplanes slammed into the World Trade Center, the Pentagon and a Pennsylvania field on Sept. 11, killing about 3,000 people.

Over the last week, top U.S. officials have issued a series of warnings of possible attacks on the United States.

Vice President Dick Cheney warned over the weekend about the probability that extremists could launch attacks on the United States.

FBI Director Robert S. Mueller III said Monday that another attack is "inevitable" and told President Bush this week that it would be difficult to stop another one.

Officials said there has been a lot of intelligence coming in over the last few weeks warning of a possible attack, but they said it varied in terms of specificity and reliability.

The FBI already warned this week of possible general threats against landmarks in New York City, including the Statue of Liberty and Brooklyn Bridge.